Please help with diagnosis

Grasscity folk -

These were taken from plants that are about 8 weeks into flowering. I've spent some time trying to identify what the cause behind these - what I'm referring to as - bleach spotting.

I believe it's either an iron or magnesium deficiency, but I don't want to treat for either without being sure, and I don't have a pro available to help.

Any advice as to what the issue most likely is and what the best solution may be would be greatly, greatly appreciated.

Thanks in advance.

 

First of all, thank you both for your responses. your experience is priceless to me, and I really appreciate your comments and suggestions.

Second of all,

Ack! Which one? Mag or Mites? I don't know how to approach resolving this. I'll upload some more pics in the event that it's helpful for the diagnosis and remedy.

Thank again to both of you and the rest of the community.

 

I appreciate that thought - my friend said the same thing. It won't make a difference for the girls just about ready to go, but I hate not finding the source of the problem to begin with. Also, I have other girls a few weeks behind, and would like to get whatever issues resolved I can while they still have a little more development to go.

I did flush tonight as a safety precaution and will let you know what ends up happening. I was very disappointed with the low ph, as I had been sustaining it at optimal levels for most the grow. So for this step:

1.) Is tweaking the ph at 8 weeks into flowering a risk?
2.) I would also be interested in your thoughts on how i should or shouldn't be checking ppm and ec, since it seems to me that these measurements are more specifically for hydro or aero. But I'm very interested in the subject, and there's a lot of contradictory information out there.

Anyway, thanks for your feedback, and please comment if you or anyone else has thoughts on what my issue is.

 

Hi guys!

Sorry for the delay. Here are few shots of the full plants.

I did find insects on and around the leaves, but they do not appear to be spider mites from what I've researched. They either translucent or light green (I'm assuming the difference is based on their age), and have longer, thinner bodies than all of the images I have seen of spider mites.

Thank you again for your help!

 

Hey zeroshadow -

Glad you're feeling chatty today!

Hopefully this will answer all of your great questions.

Temp Range: 70 - 80
Humidity Range: 45% - 50%
Air Flow: several "cooling" fans, 1 intake from the outside, and 1 6-inch inline outtake
Feeding: approximately once a week using Fox Farm (Big Bloom, Grow Big and Tiger Bloom), with occasional tbsp/gallon of molasses
Containers: 10 - 15 gallon
Lighting: 3 600-watt HPS and 1 400-watt HPS
Soil: Organic potting soil, peat moss and vermiculite mixture

Yeah, the one picture of the sorry looking guy is somewhat of an exception, but I wanted to include the worst of the worst. I think that is actually unrelated to the concerns I've been discussing (it was buried under the canopy and was not receiving a decent amount of light). Most of the other plants look quite healthy with the exception of the recent discoloration. There are several colas I can't get my hand around

Regarding the bugs, do you think it's too late into flowering to apply topical spray? And if not, do you have any recommendations for what kind of spray to apply? Would a dishwashing liquid/water solution be safe?

Lastly, for flushing, Fox Farm's feeding schedule recommends using their Sledgehammer product. Do you think using this or a similar product is necessary, or is water good enough? And how many gallons would you recommend for a 15-gallon container?

Thanks again for your help on this - I really appreciate it. Wish I could send you a sample when this crop is ready